If you have installed any mods or custom content from independent creators, this will help you. Disable all mods, [move them to a temporary [folder] outside of the The Sims 3 folder] until you have a clean running game or you will not know if your crashes are due to the game or indie custom content and/or mods effecting the game.

Delete the following files located in your C:My Document/Electronic Arts/Sims 3:

CASPartCache.package
scriptCache.package
simCompositorCache.package

Then delete all files in the WorldCaches directory

This will give your game a chance to rewrite the caches based on no installed mods or indie custom content, just official TS3 content, as some custom content and mods overwrite some content in the game and it is saved in these cache files which can cause a crash if they are not written correctly. The cache files will automatically be rewritten when you start the game. You can always re-add your custom content and mods after you have a game that runs without crashing, then if it crashes you can know that it is the game or some other technical problem such as graphics driver or graphics driver setting and not the mods or indie custom content causing the problem.

Uninstall EADM (EA Download manager)

It appears that it too is contributing to the crash. How? Only EA can answer that one, but it needs a definite fix. I will update this post as soon as a compatible EADM is tested that works, because we need the EADM to play any other games purchased through the EA download store.

Set the details to lots no higher than 4

I say no higher than 4 because I’m using an ultra fast Intel i7 975 quad core processor with two nvidia gtx295 cards (not bragging – I didn’t design the dang thing, but it is the fastest CPU/GPU processor combo available at the time of this writing) and anything higher than 4 and it crashes to desktop, so I am assuming that 4 must be the max for most multi-core processors using nvidia cards (and more than likely ATI cards as well), and as usual this may not be the case for your computer so start at a low number – test – then if no crash take it up a notch to see if your computer can take it. If it crashes, take it back down a notch.

Don’t attempt any fancy graphics card enhancements or overclocking, just leave your settings to default until you have stabilized the game. This also proved fatal when trying some fancy-pants graphics card settings.

The maximum high detailed lots when stepped down from the max [regardless of the power of your computer or graphics card], as well as uninstalling the EADM until a fix comes out for it, has successfully ended all crashing to the desktop and save errors.

Reduce high detailed lots from 16 [max] to 8 this reduced, but did not eliminate the crash to desktop and save errors. Reduced it to 6 [even less crashing] and finally  set it to 4 and this seems to eliminate ALL crashing to the desktop and even the infamous “Save error 16, 14 and 13″.

[Click here if all else fails...]